NASA's two Global Hawks – one configured as a tanker and the other as a receiver – fly in trail formation during the DARPA-Northrop Grumman autonomous UAV-to-UAV aerial refueling research project. (Northrop Grumman photo) › View Larger Image

Northrop Grumman Corp. and the Defense Advanced Research Projects Agency (DARPA), in cooperation with NASA's Dryden Flight Research Center, recently completed a research project demonstrating autonomous aerial refueling between two unmanned, high-altitude aircraft.

NASA's two Global Hawk aircraft, one outfitted as a receiver and the other as a tanker, flew a series of demonstration flights in restricted airspace near Edwards Air Force Base, Calif., between January and May 2012 to validate the advanced UAV-to-UAV aerial refueling control system technology.

Results of the DARPA-funded research effort were detailed in news releases issued Oct. 5 by Northrop Grumman and DARPA.